Jet propulsion apparatus for boats

ABSTRACT

A jet propulsion apparatus for boats wherein the inlet is mounted below the hull of the boat so that upon forward movement of the boat a ramming effect is attained which causes an increased volume of water to flow into the apparatus. The apparatus having a duct extending upwardly to an impeller chamber all of whose cross sectional areas displaced by water are equal. A centrifugal pump directs the flow into a second chamber having straightening vanes therein and whose cross sectional area displaced by the water is equal to 0.707 of that of the impeller chamber thereby increasing the velocity of water by a factor of 1.414 through said second chamber and discharged by a discharge nozzle connected thereto with an arcuate deflector member both pivotally and rotationally mounted at the discharge nozzle for steering and reversing the boat.

United States Patent 11 1 1111 3,826,217

Canova [4 July 30, 1974 i [54] JET PROPULSION APPARATUS FOR 57 ABSTRACTBOATS A jet propulsion apparatus for boats wherein the inlet lIWenIOfIHenry Callova, 1575 87th is mounted below the hull of the boat so thatupon for- Ave', Miami, 33144 ward movement of the boat a ramming effectis at- [22] Filed: Sept 10, 1973 tained which causes an increased volumeof water to flow into the apparatus. The apparatus having a duct PP 196,119 extending upwardly to an impeller chamber all of whose crosssectional areas displaced by water are 52 U.S. c1. 115/12 R, 60/221equal A centrifug? Puml? direcfs 51 1111.121 B63h 11/00 Ond chamber fstralghtfrnmg vanes them" [58] Field of Search 115/11 12 R, 12 A, 13,whose cross secnonal area displaced by the water is 1 15/14 15. 1 14/150151. 222 equal to Of that Of the impeller chamber thereby increasing thevelocity of water by a factor of 1.414

[ 56] References Cited 1 through said second chamber and discharged by adis- 1 charge nozzle connected thereto with an arcuate de- UNITED STATESPATENTS flector member both pivotally and rotationally Chl'OniC 0| Rmounted at the discharge nozzle for teering and re- 3,302,605 2/1967Kuether 115/12 R versing the boat 3,465,705 9/l969 Castoldi 115/12 R3,589,325 6/l97l Tattersall ll5/l2 R Primary Examiner-Trygve M. Blixnl'igw'mgpgggg Assistant Examiner.lesus D. Sotelo Attorney, Agent, orFirm-Salvatore G. Militana PAIENIEB JUL30l974 saw 20F a JET PROPULSIONAPPARATUS FOR BOATS BACKGROUND OF THE INVENTION 1. Field Of TheInvention This invention relates directly to jet propulsion apparatusfor propelling boats and the like.

2. Description Of The Prior Art It is common knowledge that the jetpropulsion devices for boats and the like is less efficient thanpropeller driven apparatus for the reason of the inherent design of thedevice. However, the obvious advantages derived from the use of jetpropulsion devices have caused an increasing number of boat buyers toprefer the jet propulsion manner of propelling a boat than the moreefficient propeller driven boat. The inefficiency of the jet propulsiondevice that is inherent in the device itself, of course cannot beovercome, but a larger part of this inefficiency is due to improperdesign of the jet propulsion devices.

Most, if not all of the popular jet propulsion devices have their inletmounted on the bottom of the boat, flush with the hull. This structurecompels the water to be sucked into and lifted up to the centrifugalpump. The efficiency of these devices is naturally reduced since thepump must use some of its power in bringing the water to the pump. Inaddition, the velocity of the discharged stream of water determines thespeed of the boat being driven. No attempt is made to vary the sizes ofthe inlet portion of the centrifugal pump with that of the outletportion so that an increased velocity at the discharge portion iseffected. With all other factors equal, the jet propulsion device thatdischarges the water at higher velocities will be the more efflcientdevice since the reactive forces of the discharge water determines thespeed of the boat.

A further characteristic of conventional jet propulsion devices whichtends to reduce the efficiency thereof, is the improper design of thedeflector members which fail to deflectthe stream of water with aslittle loss of kinetic energy as possible in the steering of the boat.Some such devices divert the stream of discharged water by blocking offthe discharge nozzle when it is desired to move the boat in a reardirection. The present invention contemplates avoiding all of the aboveindicated objections to the conventional jet propulsion devices andthereby produces a jet propulsion device whose efficiency closelyrelates to that of the propeller operated devices.

SUMMARY OF THE INVENTION Therefore, a principal object of the presentinvention is to provide a jet propulsion device for boats and the likehaving an inlet below the hull of the boat acting as a scoop as the boatmoves forwardly to obtain a ram effect that increases the normal intakeof water thereby.

Another object of the present invention is to provide a jet propulsiondevice whose discharge portion thereof is smaller in cross sectionalarea than that of the intake portion so that since the same volume ofwater that enters the device must be discharged therefrom, the velocityof the water being discharged by the discharge nozzle will be higher andconsequently the speed of the boat will be increased thereby.

A further object of the present invention is to provide a jet propulsiondevice for boats and the like whose steering and reverse movement deviceconsists of an arcuate deflector plate rotatably about a horizontal axisand pivoted to swing in a vertical plane for steering the boat and formovement of the boat in a rearward direction.

A still further object of the present invention is to provide a jetpropulsion device with an arcuate deflector plate that is pivotallymounted on a collar which is itself rotatably mounted on the dischargenozzle so that the deflector 'may be positioned in the path of thedischarging stream of water to effect the steering of the boat in a mostefficient manner.

With these and other objects in view, the invention will be bestunderstood from a consideration of the following detailed descriptiontaken in conjunction with the accompanying drawings forming a part ofthis speciflcation, with the understanding, however, that the inventionis not confined to any strict conformity with the showing of thedrawings but may be changed or modified so long as such changes ormodifications mark no material departure from the salient features ofthe invention as expressed in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS In The Drawings:

FIG. 1 is a fragmentary side elevational view of a boat on which ismounted a jet propulsion apparatus constructed in accordance with myinvention.

FIG. 2 is a fragmentary rear elevational view thereof.

FIG. 3 is a cross sectional view taken along the line 3-3 of FIG. 2.

FIGS. 4 and 5 are cross sectional views taken along the-lines 44 and 5-5Respectively of FIG. 3.

FIG. 6 is a fragmentary side elevational view similar to FIG. 1 showingthe deflector member of the steering apparatus in section and positionedin a neutral position.

FIG. 7 is a similar view showing the deflector member in reverse.

FIGS. 8 and 9 are top plan and rear fragmentary views showing thedeflector member in position for steering the boat to the left.

FIGS. 10 and 1 l are similar views showing the deflector member inposition for steering the boat to the right.

Referring to the drawings wherein like numerals are used to designatesimilar parts throughout the several views, the numeral 10 refers to myjet propulsion apparatus mounted on the stern 31 of a boat 11 and havinga water inlet forming a scoop 12 mounted on the undersurface of a hull23 of the boat 11. The inlet 12 is fitted with a strainer consisting ofa plurality of vertically spaced members 13 to prevent foreign matterand the like from entering the inlet 12.

The inlet 12 extending through an opening 24 in the boat hull 23 isconnected by a pipe 14 that extends upwardly and connects with a chamber15 in which a centrifugal pump 16 having a plurality of impeller blades17 is mounted thereon within a housing 49. The pump 16 is mounted forrotational movement on the end of a shaft 18 which extends through anopening 19 in the pipe 14 and is coupled as at 20 to a shaft of a motoror engine 21 (shown only in part).

The impeller chamber 15 communicates with an outlet chamber 22 in ahousing in which there ismounted a plurality of conventionalstraightening vanes 25 that force the water rushing therethrough to flowin a substantially straight line. The outlet chamber 22 is connected tothe outlet or discharge pipe 26 that extends through an opening 30 inthe transom 31 of the boat 11 whereby the discharge water effects thedesirable reactive force at the discharge outlet 27 to propel the boat11 in a desirable direction as explained in detail hereinafter. Housings49 and 50 are fastened together as by bolts 51 and supported on posts60, 60. It is to be noted that the cross sectional area of the inlet 13,pipe 14 and unoccupied area of the chamber 15 are equal so that the rateof flow of water along the full length thereof is constant. Likewise,the cross sectional area of the nozzle 27 and the unoccupied area of thechamber 22 are equal. However, the cross sectional area of the nozzle 27is 0.707 of that of the inlet 12 so that as the water is ejected bycentrifugal force by the impellers 17 at 45 angle with the axis ofrotation and the straightening vanes25 straighten the flow of water inthe chamber 22, the velocity of the water at this position and at theoutlet 27 of the nozzle 26 is increased by a factor of 1.414. Byproviding the inlet 12 below the bottom 23 of the boat 11, as the boatmoves forwardly in the water, the scooping of water by my apparatuscauses a ramming effect which not only increases the volume of flowthrough my apparatus 10 but also prevents the build-up of any pressurein the chamber thereby increasing the efficiency of my jet prupulsiondevice 10.

Mounted for rotational movement about the discharge pipe 26 is anelongated collar 32 that extends through the opening 30. The collar 32is provided with bearing races 33, 34 and thrust bearing 35 to permitthe collar 32 to rotate with ease about the pipe 26. The bearings 33 and35 are supported within housings 37 and 38 secured by bolts 39 extendingthrough the transom 31. A radially extending tab or tiller 36 mounted onthe inner end portion of the collar 32 within the boat 11 is connectedas at 141 by a cable 40 that extends within a pipe 48 to anoperatinglever (not shown) for steering the boat 11. On the outer end ofthe collar 32 there is a pair of longitudinally extending tabs 41 towhich an arcuate deflector member 42 is pivotally mounted as at 43. Thedeflector member 42 is provided with an actuating arm or lever 44fastened at one end thereto and having its outer end portion connectedas at 45 to a cable 46 for pivoting the deflector in a vertical plane.The cable 46 mounted in a pipe 47 extends through the opening 30 in thetransom 31 and is connected to an operating lever (not shown) which inconjunction with the tiller will steer the boat 11 as is explainedhereinafter.

In the normal operation of my jet propulsion apparatus 10, the motor 21is operated to cause the shaft 18 and centrifugal pump 16 to rotate.Water is drawn through the inlet 12, into the pipe 14 and chamber 15 tobe ejected into the chamber 22 by the pump 16. The water then flowsthrough the pipe 26 to be ejected at the discharge outlet 27 in a solidjet whose reactive force causes the boat 11 to move in a forwarddirection with the deflector plate 42 out of the path of the dischargedjet of water and positioned as shown by FIG. 3. Now if it is decided toturn the boat 11 to the left, the cable 46 is pushed so as to cause thedeflector member 42 to pivot downwardly into the path the jet of waterbeing discharged by the nozzle 27 and the cable 40 is pulled to causethe collar 32 and deflector member 42 to rotate about the pipe 26 to thedotted position to the right as seen in FIG. 4.

If it is desired to turn the boat 11 to the right as it moves forwardlyin the water, the deflector member 42 is again made to pivot about thepivotpins 43 in a vertical plane in order to intercept a portion of thejet of water being ejected by the nozzle 27. Then the cable 40 isactuated to push the tab 36 and rotate the collar 32 to the dotted lineposition shown on the left as seen in FIG. 4. The deflector member 42assumes the position as shown by FIGS. 10 and 11 to cause the forwardlymoving boat 11 to turn to the right. If it is desired to maintain theboat 11 motionless while the jet motor 16 is operating, the deflectormember 42 is positioned in the path of the jet of water being ejected bythe nozzle 26 and directing the flow of water directly downwardly asshown by FIG. 6.

While the boat 11 is in this motionless position, the stern can bemanoevuered from one side to the other by rotating the collar 32 whichcauses the deflector 42 to rotate about the axis of the discharge pipe26. If the operator of the boat wishes to move directly astern, hepushes the cable 46 to pivot the deflector member 42 to its downmostposition as shown by FIG. 7, the jet of water striking the arcuate plate42 will be deflected below and forwardly of the boat 11 to cause theboat 11 to move rearwardly. By manipulating the cable 40 to pivot thecollar 32 in either rotational direction, the boat 11 can be made toturn in either direction as the boat 11 moved rearwardly.

What I claim as new is and desire to secure by Letters Patent of theUnited States is:

1. A jet propulsion apparatus for boats and the like comprising a waterinlet mounted on the lower surface of the hull of a boat, a ductextending upwardly from said inlet, an impeller chamber connected tosaid inlet, centrifugal water impeller means mounted in said chamber,power operated means connected to said water impeller means, a secondchamber connected to said impeller chamber, straightening vanes mountedin said second chamber, a discharge pipe connected to said secondchamber and extending through an opening in the stern of said boat,collar means rotatably mounted on said discharge pipe, and waterdeflector means pivotally mounted on said collar means adjacent anoutlet of said discharge pipe whereby said boat may be steered uponpivotal and rotational movements of said deflector means in the path ofwater being discharged by said discharge pipe, sajd deflector meanshaving an arcuate deflector plate, tab means extending at substantiallyright angle alongeach edge of deflector plate and a pivot pin pivotallymounting each of said tab means to one end of said collar permittingsaid deflector plate to swing in and out of the path of flow of waterbeing discharged at said outlet.

2. The structure as recited in claim 1 taken in combination with secondtab means mounted on the other end of said collar and operating meansconnected to said deflector plate and said second tab means forrotational and pivotal movement of said deflector plate in steering saidboat.

1. A jet propulsion apparatus for boats and the like comprising a waterinlet mounted on the lower surface of the hull of a boat, a ductextending upwardly from said inlet, an impeller chamber connected tosaid inlet, centrifugal water impeller means mounted in said chamber,power operated means connected to said water impeller means, a secondchamber connected to said impeller chamber, straightening vanes mountedin said second chamber, a discharge pipe connected to said secondchamber and extending through an opening in the stern of said boat,collar means rotatably mounted on said discharge pipe, and waterdeflector means pivotally mounted on said collar means adjacent anoutlet of said discharge pipe whereby said boat may be steered uponpivotal and rotational movements of said deflector means in the path ofwater being discharged by said discharge pipe, said deflector meanshaving an arcuate deflector plate, tab means extending at substantiallyright angle along each edge of deflector plate and a pivot pin pivotallymounting each of said tab means to one end of said collar permittingsaid deflector plate to swing in and out of the path of flow of waterbeing discharged at said outlet.
 2. The structure as recited in claim 1taken in combination with second tab means mounted on the other end ofsaid collar and operating means connected to said deflector plate andsaid second tab means for rotational and pivotal movement of saiddeflector plate in steering said boat.